Eye dilation from eye drops used for examination of the eye usually lasts from 4 to 24 hours, depending upon the strength of the drop and upon the individual patient. Pupil dilation tends to last longer in people with lighter colored eyes, since brown pigment in the iris is essentially the only eye pigment, blue eyes lack significant color and gain their blue shade from light reflecting in the iris. Pigment binds the dilating drops and requires higher doses but blue eyes react faster and stronger to dilation drops. Occasionally a child’s eyes may stay dilated for longer than 24 hours. Children require stronger and longer lasting drops than do adults to accurately measure refractive error. Dilating eye drops are occasionally used to treat certain eye diseases such as amblyopia and inflammation in the eye. These therapeutic dilating drops may have a longer duration of action, even up to 2 weeks. Despite the longer duration of action, daily administration of the drop may be necessary for treatment.
What are dilating eye drops?
Dilating eye drops contain medication to enlarge (dilate) the pupil of the eye. There are two types of drops: one type stimulates contraction of the muscles that enlarge the pupil (such as phenylephrine); the other type relaxes the muscles that make the pupil constrict and also relaxes the muscle that focus the lens of the eye (such as cyclopentolate). These two kinds of medications are often used together, either as two separate drops or as a single combination drop.
Why is eye dilation necessary?
In Medford, a large dilated pupil allows your doctor to examine the inside of the eye in order to diagnose and treat eye diseases. Also, relaxing the focusing muscles of the eye allows for a more accurate measurement of refractive error (need for glasses) in children.